Yup,
Ettercap would do the trick. Now that is one nasty tool!

a little off this subject, but since you brought up wireless.....

You can now buy jammers (a bit bigger than a bottle cap) that can bring down a WAP in a second. The kill radius is something like 100m. They are totally illegal in the US (any jamming device is) and are easily dedected by a spectrum analyzer and antenna. But for the time they are working, the wireless network would be totally useless.